Feminists have vandalized a plaque commemorating the two men who discovered the structure of DNA, Francis Crick and James Watson.

The sign, which is outside The Eagle pub in Cambridge, England, commemorates the double helix discovery Watson and Crick made in 1953. The sign has “+Franklin” scrawled on it, a reference to chemist Rosalind Franklin’s work, which was also instrumental in the discovery.

Franklin died of ovarian cancer in 1958, five years after the discovery was made public.

Franklin’s name was spotted by Cambridge University linguist Andrew Caines, who took a picture of it. “I was just walking past and I noticed the graffiti and took a photo,” he said in an interview with the Cambridge News. “I knew the plaque was already there, but that was the first time I saw it.”

Watson, Crick and Maurice Wilkins received the 1962 Nobel Prize in Medicine for their work, but Franklin was not included.